The dome-shaped tunnel has dimensions of 0.9m x 1.75m (Photo: VNA)

The hall serves as a place for meetings, arts performance and movie screening (Photo: VNA)

Information board for people living in the tunnel (Photo: VNA)

During wartime, 16 children were born here (Photo: VNA)

Rooms for 3-4 member families (Photo: VNA)

Tourists explore the trench system (Photo: VNA)

Trenches connect the tunnel doors (Photo: VNA)

The complicated network of trenches surprise  tourists (Photo: VNA)